1. Field of the Invention
The present invention relates to a tone hole pad for a musical wind instrument which is mounted within a cup for opening or closing a tone hole and a method of touch (feeling) adjustment therefor.
2. Description of the Prior Art
In an old style musical wind instrument (until about 1800), the diameter of tone holes formed on side face thereof is very small and a distance between the tone holes on both sides is short so that the holes can be reached by extending a finger. An instrument player changes a produced sound by changing the effective length of a wind instrument pipe by opening or closing the tone holes directly. Because a finger pad is deformed corresponding to the shape of the tone hole, the tone hole can be sealed completely with a light touch (pressure).
However, to produce accurate half tones or generate larger sounds, various modifications were applied to wind instruments so that their length was gradually increased. As a result, the diameter of the tone hole has increased and the distance between the tone holes on both sides has tended to increase in order to create todays style of wind instruments. Because of this style, a tone. hole cannot be opened or closed directly by a finger. Today's wind instruments have been constructed so that when a lever is pressed by a finger, the generated force is transmitted via the lever and applied and applied onto the top face of the tone hole. The tone hole is then opened or closed by a pad mounted on an inner face of a cup.
As a result of a number of trial productions, a currently standard pad (about 3 mm in thickness) has the following structure (see FIGS. 14-15). A piece of felt 21 (about 2 mm in thickness) is mounted on a mount paper 22. A pad skin 23 (thin cover) is then placed so as to wrap the felt 21 and is glued to the mount paper (about 1 mm in thickness). A hole 25 is located in the center of the pad (see FIG. 14). A side of the mount paper 22 of the pad is mounted in a cup 24 and another side of the felt 21 contacts the tone hole.
The pad is inserted in the cup 24 and a pad nut 26 is inserted into the hole 25 for mounting in the center of the pad. Then, a pad washer 27 having a smaller outer diameter than the tone hole is placed thereon and finally tightened with a pad fastening screw 28 to the cup 24. A gap between the pad and cup 24 is filled with adjustment paper 29 (see FIG. 15). Adjustment to a desired finger touch for an instrument player is done by reducing the thickness of the felt 21 or using a rigid felt 21 so as to harden the touch, or by increasing the thickness the felt 21 or using soft felt 21 so as to soften the touch.
The above-described conventional wind instrument pad and touch adjustment method have the following problems.
One of the problems is that the pad cannot cope with distortion of the tone hole so that a gap is produced therearound. The tone holes of the wind instrument are cylindrical holes formed integrally on a side face thereof. In a metal instrument, it is almost impossible to process a top face of the tone hole completely flat. Therefore, some distortion is always produced. In a wooden instrument a mountain portion and a valley portion are formed on the top face of the tone hole because of distortions in the wood and the grain of the wood. The pad does not come into firm contact with the valley portion due to these distortions, and thereby produces a gap.
Another problem is that the cup supporting the pad cannot be mounted completely parallel to the tone hole. Because the cup makes a circular motion around a fulcrum of a lever, if the pad is thick, a portion of the pad near the fulcrum comes into contact with the tone hole so that a gap is produced in a portion of the pad away from the fulcrum. In case of a thin pad, a portion of the pad away from the fulcrum comes into contact with the tone hole so that a gap is produced in a portion of the pad near the fulcrum.
Still another problem is that the felt occupying most of the pad cannot maintain a constant shape so that the pad is deformed, and consequently the pad itself is also deformed and cannot be restored. As a result, a firm contact with the tone hole is lost. Because the felt is as thick as about 2 mm, the deformation thereof largely affects the fin contact. The felt is likely to be affected by the humidity, and if the humidity rises, the felt absorbs water so as to become thicker. If the humidity drops, the felt is dried and contracted. Further, the felt is physically pressed by pressure applied when the instrument is played, so that it is deformed. In the deformed felt surface, a dented valley portion and a swollen mountain portion are generated. If the pad is deformed and deteriorated, it is not capable of closing the top face of the tone hole properly so that there is produced a gap therearound.
Still another problem is that to intensify contact performance between the pad and tone hole, instrument players must increase their finger touch (pressure) using only the elasticity of the felt. To produce a better sound by accommodating the distortion of the tone hole and deformation of the pad, the pad needs to be pressed firmly against the top face of the tone hole so as to close it. However, when a quick passage is played, it is difficult to enhance the finger touch. Additionally, a violent and strong touch quickens deterioration and deformation of the pad. It is found that a wind instrument player needs to have more physical strength and technique than properly is required. Further, sound produced by the contact between the pad and tone hole by a strong touch produces noise. Although it is ideal that the player can obtain a feeling that the tone hole is completely closed with the player's finger through the pad, the finger does not receive such a feeling that it is completely closing the tone hole, because the cup needs to be pressed firmly.
A further problem is that a slight amount of air may invade through a gap between the pad surface and rear surface of the pad washer, pass through a gap between a pad hole and pad nut, and leak out through a gap between an outer peripheral face and the cup (including the adjusting mount paper) from the pad rear surface. This, also, results in deterioration of sound quality.
A further problem is that the mount paper deflects from the center of the pad, because the felt and mount paper are not fastened. Consequently, a deflection occurs due to the tension of the pad skin so that the pad shape cannot be maintained properly, and the pad is deformed so as to produce a gap.
A further problem is that pressure for mounting the pad is not uniform. Only the center portion of the pad is pressed firmly against the cup by a pressure of the pad washer. Because the felt and mount paper of the pad are not hard, pressure of the pad washer is concentrated around the center of the pad and it is weaker near the periphery thereof. Because the pad is warped and the periphery thereof is distorted by the deflection due to the pressure, there is produced a gap between the pad and tone hole so that the pad cannot have a firm contact.
A further problem is that air leaks so that an accurate sound is not produced. Unless the tone hole is closed completely by the pad, no accurate sound can be produced. The conventional pad cannot close the gap completely and is incapable of producing an accurate sound.
A further problem is that it is periodically necessary to carry out fine adjustments of the unevenness produced on the surface of the pad by creating an uneven inner surface of the cup, by mounting an adjustment paper, and by mounting the pad thereon. In this adjustment, an adjustment paper having a thickness of about 0.005 mm is mounted on the inner surface of the cup which contacts a retracted portion of the tone hole so as to produce unevenness on the surface of the pad. This work requires skill and time. Although this fine adjustment allows the tone hole to be closed firmly, the pad is deformed and deteriorated, because of the aforementioned reasons so that a gap is produced. In the worst case, with a single play after such a fine adjustment, the generation of accurate sound is disabled.
A further problem is that adjustment of the touch requires skill, and that thick soft felt tends to be largely deformed while thin solid felt tends to have lower contact performance. Further, there is a problem that other touch characteristics (other than solid and soft) such as shallow touch or deep touch cannot be adjusted.